Grit Blogs > Acorn and Thistle

Frost Protection

Acorn and ThistleIt’s getting to be that time! As we draw closer to the end of October, the temperatures are dropping a little more each day. According to my calendar, in previous years we’ve seen our first frost here at the house any time between this past Sunday (10/26) and November 7th. While that doesn’t guarantee that we’ll have frost this year during the same time frame, it does mean that it’s time for me to gather up my frost gear for the garden.

I keep a box of light frost blankets standing by the back door, ready in case the temps suddenly dip. These blankets have a drawstring bottom and slip easily over the tops of my raised beds - I’ve already prepped the areas needed with a good layer of mulch and some PVC hoops, so I’m not totally rushing when the forecast changes. The blankets are a breathable poly fabric, and work well for the lighter frosts we see this time of year.


Fortunately, here in the Pacific Northwest, our winters are typically quite mild and frost protection doesn’t have to get too involved. I do have some heavier duty green frost blankets for the inevitable week or two of really cold weather that we get periodically; those can get tossed right on top of the white ones already in place, for some extra help. The nice thing about the darker ones is that they help draw in some more heat when the sun is shining, which is perfect for our weather patterns here.

Plastic can also be used, but it needs to be raised up high enough off the plants so they aren’t touching each other, or else the plants will freeze wherever the plastic is in contact with them. In a pinch, I think it’s better to break out some old sheets instead of the plastic - they’re breathable like the poly blankets and can be in contact with your plants without worry. Plastic also needs to be opened in the daytime when the sun is shining, so that the heat doesn’t build up too quickly and harm the plants.

In researching other frost protection options, I came across a recommendation to use mylar space blankets in extreme cold situations. These blankets will retain much more of the soil’s heat overnight, but they need to be removed in the daytime to allow the soil to recharge. Space blankets are relatively inexpensive, and can be found anywhere camping gear is sold. 

Another idea I saw was to use Christmas lights inside a plastic cold frame, to help heat the space when the mercury really gets low. That seems like overkill here for the most part, but in places with extended periods of very cold weather, that sounds like it could be a great option!

What about you: Do you use frost blankets or other season-extending items in your garden, or do you just put it all to bed for the winter?